Treating textiles and oils therefor



Patented Dec. 19, 1939 E S P No. 161,530. In 1936 6 Claims.

This invention relates to improvements in treating textile materials andmore particularly those consisting of or containing animal hairs. Theinvention further relates to improvements in the treatment of oi s andwaxes and especially Great Britain August 31,

ONV (diphenyl carbamyl dimethyl dithiocarbamate).

Thiuram DS.

Diphenyl thiourea.

Thiourea metho sulphate.

those containing unsaturated glycerides or un- Thiocarbanilide.saturated esters or unsaturated acids or unsat- Thio semi carbazide.urated alcohols, or oily or waxy materials of Thio acetanilide.

similar composition, for example olive oil, arachis Thio diphenylamine.

oil, oleic acid, cyclohexanol oleate, diglycol oleate,-Tetraethylthiuramdisulphide. m

oleyl alcohol and sperm oil. Mercaptobenzthiazole.

The unsaturated constituents are liable to oxi- In each s 0 1% of thecompound was added dation especially in presence of naturally occur-Most of these coinpounds are accelerators of ring catalysts, which mayinitiate or accelerate canisation of rubber strongly exothermicreactions in the Mackey test, e5

Jour. Soc. Chem. Ind., 1896 (15), 90. It is generally considered thatthe suitability of an oil for W001 combining or like purposes isindicated by the absence of any pronounced exothermic oxidationreactions in the Mackey test.

According to the invention the oil is modified by treatment with certainsubstances hereinafter defined in such a manner that these exothermicoxidation reactions are hindered or reduced in violence or stopped.

The invention particularly consists in processes in which such oils andwaxes are treated with sulphur or sulphur compounds as oxidationinhibitors.

bamates, thiurams, thiazoles.

Examples of suitable sulphur compounds, which have been tested and foundsatisfactory are:

A particularly important feature of the invention consists in treatingthe above described oils with sulphur itself to inhibit oxidation.

It is found that such inhibition can be brought about by dissolvingsmall amounts of elemental sulphur in the oil. At ordinary temperaturessolution is very slow, but can be accelerated by heating, and isreasonably rapid at 110-130 C. An oil treated by mere solution of thesulphur resists oxidation much better than the untreated oil,v

but has the disadvantage for some purposes that certain metals, e. g.,mercury, copper, lead, in contact with it are rapidly stained even atnormal temperatures. I

This invention therefore includes also the in- 200 C, the sulphur firstmelts into small globules and these then react locally with the hot oilto form very dark brown bodies not easily dissolved which' when insolution, colour the oil, especially if subjected to local overheatingby continued contact with the sides of the heating vessel. Undulyprolonged heating at an unnecessarily high temperature also causesexcessive darkening; the use of a'large excess of sulphur is also to beavoided.

The invention further consists in treating texcorporation of elementalsulphur in such a 30 we metenals f the modlfied, e n'er that the 011does not stain metal surfaces. The eorflmerele'ny Suitable, mhlbitorspossess This can be, done by heating the oil containing the P? generalpfopertlesdissolved sulphur to above a critical temperature Solublhty mthe to at least which varies with different oils, but is below about 52. Addition of not more than 1% to a solution C fo most Vegetable oilsThe sulphur 55 of 0.1% ferric oleate in pure ethyl oleate is sufparentlycombines t some constituent ofthe ficient to reduce the extent of therise in tem- 11 and practically no staining of mercury, perature abovethe 212 F. in the Mackey testper or lead occurs at normal temperatures.

Within the above limitations the following Such products though theyresist oxidation 40 40 classes of substances may be employed asinhibmuch better than untreated oils may have the itors: disadvantageforsome purposes of a dark colour (a) Sulphur. if the sulphur additionbe not made using cer- (b) Mercaptans, disulphides, tnioureas, guani- Wprecautionswhen an pt de to dines, carbamates, thiocarbamates,dithiocardlssolve 4 fi bflmstone m an 011 at 45 This invention includesalso the incorporation of elemental sulphur in such a manner that theoil is not unduly darkened in colour as a result of heating to the hightemperatures necessary to prevent staining of metals in the cold.

This can be done by proceeding in one of the following ways: 1

1. The sulphur may be in complete solution in the oil below the criticaltemperature for the oil, and preferably below 125 C., before heating toabove the critical temperature, e. g., to 180 C.

2. The sulphur may be added to the 011 maintained at a temperature abovethe critical temperature for the oil, e. g., at 180 C., in the form of aconcentrated solution of sulphur in the oil.

3. The sulphur may be added to the oil maintained at a temperature abovethe critical ternperature for the oil, e. g., (for linoleic acid) at 180C. in a form which dissolves rapidly at this temperature (e. g., as asuspension of fine crystals obtained by dissolving sulphur in a portionof the oil blow 125 C. and cooling rapidly to C.)

4. The sulphur may be added according to Method 2 but as a concentratedsolution in a volatile solvent such as carbon disulphide, followed bysubsequent removal of the solvent by evaporation or distillation.

Example. 1

The use of sulphur as an antioxidant may be illustrated by the followingexample relating to refined arachis oil.

Five parts sulphur are dissolved in 100 parts of the oil at 120 C. withstirring. This solution on cooling rapidly to 20 C. deposits crystals ofsulphur which are very easily soluble in a suificiency of hot oil, oreven cold oil.

1,900 parts of the oil are heatedto 200 C. and the above 100 parts ofoil containing 5 parts of sulphur either in hot solution or coldsuspension are added with stirring. The oil is maintained at 200 C. forabout half an hour and is allowed to cool.

Alternatively the above 100 parts of oil containing 5 parts sulphur inhot solution are added to 1,900 parts of oil at room temperature, thetemperature raised to 200 C. and'maintained at the temperature for a fewminutes.

The product does not stain copper cold, or even when heated in contactwith the metal except after heating at high temperature. The refining ofthe raw oil removes bodies which would cause darkening.

Example 2 A commercial oleic acid preferably vacuum distilled inapparatus constructed, so far as those parts coming into contact withthe acid are concerned, of metals which do not form dark col ouredsulphides, is treated as in the preceding example. The resultant productis of increased stability to oxidation. When saponified by means ofsolutions of mild alkalis such as sodium carbonate the treated acidforms soaps which practically speaking are free from sodium sulphide;such soaps are more resistant to air oxidation than soaps made from theuntreated acid and their aqueous solutions do not blacken copper orlead.

In general, the production of a lightor medium-coloured oil depends onobservance of the following points:

(a) Vacuum distillation to remove pitch.

(b) Heating at the lowest temperature which will produce a non-stainingoil.

(0) Using the minimum amount of sulphur which will give a good Mackeytest.

(11) Heating at the high temperature for as short a time as will give anon-staining oil, since the non-staining inhibitors appear to decomposeby heating to form highly coloured bodies.

I declare that what I claim is:

1. Process of producing a non-staining textile oil not darker than amedium colour which comprises incorporating in a textile oil containingunsaturated substances a small proportion of solid sulphur of the orderof 0.1% to 0.25% and heating the mixture at the lowest temperature whichwill produce a non-staining oil.

2. Process as in claim 1 in which the sulphur is completely dissolved inoil at a low temperature before heating to produce a non-staining oil.

3. Process as in claim 1 in which a concentrated solution of sulphur isadded to a body of WALTER GARNER.

